Silicon W Calorimeters for the PHENIX Forward Upgrade

Transcription

1 E.Kistenev Silicon W Calorimeters for the PHENIX Forward Upgrade

2 Event characterization detectors in middle PHENIX today Two central arms for measuring hadrons, photons and electrons Two forward arms for measuring muons

3 How PHENIX works Spectators 1-15% 5-1% -5% Participants South Muon Magnet Central Magnet North Muon Magnet Peripheral Central ZDC South MuID MuTr BB MVD ZDC North MuID South Blick von der Seite North Centrality selection : Sum of Beam-Beam Counter (BBC, η =3~) and energy of Zero-degree calorimeter (ZDC) Extracted N coll and N part based on Glauber model.

4 History lessons and future directions The devil in the details: PHENIX needs luminosity, acceptance and sensitivity to right probes -PHENIX contribution to sqgp discovery heavily relied on p and direct g measurements in central electromagnetic calorimeters: build on success extend acceptance for electromagnetic probes; -All experiments at RHIC measure jets only indirectly via leading particles. Include direct jet measurements whenever possible; -Use unique feature of PHENIX: muon spectrometer Optimal strategy for upgrade: Convert PHENIX Forward Muon System into PHENIX Forward Spectrometer

5 PHENIX Upgrade

6 Constrains -space cm from collision vertex cm total depth -no tracking upstream (momentum and charge unknown) Goals -Reasonable energy resolution for em probes; -Best possible separation between em and hadronic signals -Ability to reconstruct p s to ~3 GeV/c -Jet identification and cone energy measurements for lepton tagging and isolation testing

7 NCC tracking calorimeter Parameter Value Comment Distance from collision vertex Radial coverage Geometrical depth cm 5 cm ~19 cm Absorber W Lrad or 1.6 Labs Readout Calorimeter Preshower detector (PS) Si pads (15x15 mm) and pixeleted strips (..5x.5 mm pixels grouped into 6 mm long strips) EMC(1 sampling cells: 3mm W +.5 mm readout) longitudinally structured into two identical nonprojective sections. Leakage(6 sampling cells: 15 mm W +.5 mm readout) Lrad W converter followed by a stripixel layer (.5 mm strips) with -d readout Shower max detector (SMD) In between two EM sections at ~ 7 Lrad depth. Stripixel layer (.5 mm strips) with -d readout Multiple scattering in NCC combined with Fe magnet pole Expected EM energy resolution % Expected jet energy resolution % Two showers resolved at in calorimeter ~/sqrt(e) ~1/sqrt(E) 3 cm 133 MeV To compare with 16 MeV in the existing configuration with Cu NoseCone in preshower mm In simulation effective for shower separation down to mm in shower max. mm

8 -d pixilated strip sensors Pad-structured sensors EM Segments Hadronic Segment strips 3 GeV/c π in NCC towers

9 Design optimization -Total depth fixed to 19 cm -Three segments (EM1/EM/Hadronic) -Plate thickness in EM segments varied from mm up in steps of.5 mm -Plate thickness in Had segment is whatever fits the total depth limit

10 Design optimization: electromagnetic vs hadronic -correlations between plate thicknesses in em and hadronic segments push towards thicker plates in em segments; -Optimal em resolution and discrimination power is reached for W plates in em segments 3 mm or thicker; -For a fixed total calorimeter depth there could be advantages to using Pb instead of W in hadronic segment.

11 π > > γ γ 5.3 GeV/c π > > γ γ 9.5 GeV/c

12 P recognition/reconstruction Select clusters of amplitudes in all segments; Combine energy ordered clusters from different segments into tracks Define regions of interest in PS and SM foe every cluster (cluster energy dependent); Discount clusters with only one hit in PS, for multiple hits in PS compute separation between two hottest hits; Select two clusters in SM (constrained by hit separation in PS) and fit energy ratio; Use total track energy, hit separation from PS and energy ratio from SM to compute effective mass; Retain those within p window as p candidates, build effective mass combinatorics among everything else.

13 Claims to substantiate Single-particle (π and e) simulation in NCC

14 π losses today π efficiency today

15 R&D -5: BNL-MSU-UCR-RIKEN DC coupled, pad structured - completed AC coupled, pad structued - completed DC coupled, r-biased, pad structured at ELMA and ON Semi StriPixels 5 µ

16 Depletion voltage for 3 mkm sesors /C^ Total dark current, na Series1 Series Bias voltage 3 1 I vs V Bias voltage, V

17 7 Current and Capacitance at 5V 6 5 Current, pa Capacitance, nf Pad number

18 We can really do it

19 Eneregy resolution Positron run 39 Event Plane Plane Positron run / 11 P P 39. P P P P6.858E-5 P E-8 P8.897E Plane Plane Plane Plane Amplitude sum

20 Pointing resolution Position resolution [cm] Depth at the segment center [X ] Events/θ 9 X 8 7 σ = [mrad] 8 Y 7 6 σ = [mrad]

21 R&D to complete 6-7 R&D 6-7: Development 6(k$) 7(k$) Total(k$) Funding source Pxilated strip sensors (StriPixels) 6,3 6,3 RIKEN R&D Pad-structured readout units 18,565 18,565 DOE Generic R&D Strip-structured readout units 5, 15,, RIKEN R&D Pad readout analog elecronics 15, 15, RIKEN R&D Pad readout digital electronics 3, 5,813 8,813 DOE Generic R&D StriPixel readout electronics, 8,5 1,5 RIKEN R&D R&D 6-7: Design and Prototyping Mechanical Design 6, 6, UCR R&D Pad-structured sensors 7,,531 9,531 RIKEN R&D Pad-structured ROU's 5, 19,33,33 DOE Generic R&D Electronics for pad-structured layers 1, 7,5 37,5 DOE Generic R&D Pixilated strip sensors (StriPixels) 1,5 1,5 DOE Generic R&D StriPixel ROU's and electronics 18,185 18,185 DOE Generic R&D Mechanical Structure 5, 8,85 13,85 DOE Generic R&D Testing (bench and Test beam) 17,38 17,38 DOE Generic R&D 6-7 request to DOE 1,565 17,7 18, request to RIKEN 15,3 6, ,81 Others (UCR) 6, 6,

22 Project at a glance Funding Source Base cost Contingency [%] Overhead [%] Cost to Project DOE Generic R&D Funds $1, $16,33 RIKEN R&D Funds $138,5 1 $15,5 UCR R&D Funds $5, $6, MSU R&D Funds $ $ JINR (Dubna, Russia) R&D Funds $ $ Czech group R&D Funds $ $ Korean group R&D funds $ $ DOE Construction Funds $,31, $3,83,5 Collaboration construction funds $,386,63 $3,6,8 NCC Project $5,189, $8,31,3

23 Summary There is a lot of momentum Next two years are To substantiate the performance claims; To accumulate data to build analysis chain; To finish design and test production chain; Three years for construction project are tough but feasible. We can get to the physics of saturation in 1.